RV-10 max HP rating

[charlotte94]

I am repowering Haka Le.  Can anyone tell me what is the max HP for the RV-10?  Also has anyone repowered with a 50hp and kept the RV-10?   My Mech wants to put in a Volvo-pentra D2-50 or 50 hp.  I tried calling walter but they are closed for a few days       Thanks for any help out there

[Jim S]

The 50 hp engine will most likely overpower the R-10.  When I repowered my 365, I considered the Westerbeke 44Bfour which was borderline with a new R-10 V-drive, and was not suited for a 25 year old R-10..    My opinion is that a 50hp engine in the 365 is overpowering the entire boat unless you are using the engine to drive other activities: refrigeration, special alternators, etc.  Shaw/Pearson used the W40 for a reason, it fit.

[charlotte94]

Jim:   Thanks so much for your help.  I was on the same side of the fence as you.  You deff helped me confirm this.  Very much apricated

[Jim S]

I repowered in 2005 using a Westerbeke 35Dthree, 1.48:1 Hurth HBW 100 transmission, a Walters RV-10 (1.67:1) v-drive and a Baumann Sail III 18x13RHP propeller.  The repowering reversed the rotation of the propeller and increased torque on the propeller shaft.  After repowering, the 1 1/8" original bronze propeller shaft whipsawed in the stern tube causing knocking above 1800 rpm and I replaced the shaft with a 1 1/8" Aquamet shaft. 

We cruise in the Texas ICWW and coastal bays and find that we get 6-7 mph at 2000 rpm under power alone for fuel usage of about 1/2 gph.

I was able to remove the engine dockside by removing the engine box enclosure and part of the starboard storage box.  I did not remove any of the galley cabinetry.  I hoisted the engine using a 2 ton chain hoist attached to the mast with halyards backing up the load.  We swung the engine over to a dolly on the dock and reversed the procedure to install the new engine.

[charlotte94]

Thanks a bunch Jim this will help a lot

[Jim S]

three blade propeller

[PeteW]

Within limits of size and weight it becomes difficult to overpower a 365. But regarding the RV10 you can definitely over-prop. Without maintaining the 1:1 gear ratio in the gearbox and 2:1 in the RV10 input torque rating will be exceeded depending on prop size. I have a Westerbeke W58 with a 1:1 Borg Warner  and an RV10 2:1. I've gone over all the specs from Walter and it's close. I've pitched the he prop up an inch so I can cruise at a lower RPM. Pretty sure my motor is loafing along at 1800 RPM.

I've posted plenty on this repose topic which should still be out  there.
Regards Pete

[charlotte94]

Thanks everyone .   I do appreciate the advice.  I took charge and am now repowering with a beta 35 @2800 rpm a direct drive borg werner velvet drive tranny   The people at beta marine have done several 365's      The only issue is I will need to re-pitch my 3 blade prop from 17X10 to 17X12